Tow truck conveyor system

ABSTRACT

A low truck conveyor system comprising a plurality of tow trucks movable along a floor having a slot therein. A conveyor is driven within the floor beneath the slot and has driving means thereon for engaging a tow pin on the tow truck to move the tow truck along. A track is provided for the conveyor and a portion of the track is adapted to be moved laterally to cause the tow pin to engage a cam portion for camming the tow pin upwardly and out of engagement with the driving means on the conveyor.

United States Patent Haase et al.

[ 1 June 13, 1972 [54] TOW TRUCK CONVEYOR SYSTEM [72] inventors: Robert Haase, Troy; Karl R. M. Karlstrom, Roseville, both of Mich.

American Chain 8: Cable Company, Inc., New York, NY.

[22] Filed: Jan. 23, 1970 [21] AppLNo; 5,234

[73] Assignee:

[52] U.S.Cl..; ..l04/l72 BT l Int. Cl ..B65g 17/42 [5 8] Field of Search 104/ 1 72 BT [56] References Cited UNITED STATES PATENTS 3,520,255 7/1970 Hefler ..l04/l72 BT Primary Examiner--Drayton E. Hoffman Assistant Examiner-Robert Saifer Attorney-Bames, Kisselle, Raisch & Choate 57 ABSTRACT A low truck conveyor system comprising a plurality of tow trucks movable along a floor having a slot therein. A conveyor is driven within the floor beneath the slot and has driving means thereon for engaging a tow pin on the tow truck to move the tow truck along. A track is provided for the conveyor and a portion of the track is adapted to be moved laterally to cause the tow pin to engage a cam portion for camming the tow pin upwardly and out of engagement with the driving means on the conveyor.

18 Claims, 8 Drawing Figures PATENTEDJUH 13 I972 SHEET 1 OF 4 INVENTORS OBERT HAASE RL R. M. KARLSTROM I ATTORNEYS PATENTEDJUH 13 1972 SHEET 2 OF I INVENTOR HAAS E ROBERRT KARL .M. KARLSTROM ATTORNEYS PATENTEnJuu 13 I872 FIG. 3

SHEET 3 BF 4 F:' i I Vi FIG. 5

FIG. 4

' OB RT I E TQRS ARL. RJVL KARLSTROM ATTORNEYS PATENTEDJIJN 13 I972 SHEET H11 4 FIG. 8

INVENTORS OBERT AASE QRL R-M. KARLS'TQOM ATTORNEYS This invention relates to tow truck conveyor systems.

' BACKGROUND OF THE INVENTION In tow truck conveyor systems wherein tow trucks having tow pins thereon are driven by engagement with a conveyor positioned beneath aslot in the floor through which the tow pin-extends into engagement with the conveyor, it is often desirable in order to perform various operations on the load on the tow truck to stop the tow truck. One of the main means utilized is to provide means on the tow truck that is operable to lift the tow pin.

In the copending patent application of Karl R. M. Karlstrom, Ser. No. 795,589, filed Jan. 31, 1969, and titled Tow Truck Conveyor System, now US. Pat. No. 3,606,840, issued Sept. 21, 1971, there is disclosed and claimed a system which includes a chain track that is movable transversely with respect to the longitudinal movement of the chain along the track to move the tow pin into and out of the path as it approaches the movable portion. 7

Among the objects of the present invention are to provide an improved apparatus of the type disclosed in the aforementioned patent application for lifting the tow pin which is operable in the floor rather than on the tow truck; which is'relatively simple in construction; which has relatively long life; which will insure the lifting of the tow pin and re-engagement with the conveyor as desired.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary part sectional view of a portion of a tow truck conveyor system embodying theinvention.

FIG. 2 is a fragmentary part sectional view similar to FIG. 1 showing the parts in a different operative position.

FIG. 3 is a partly diagrammatic plan view of a tow truck conveyor system embodying the invention.

FIG. 4 is a fragmentary sectional view taken along the line 4-4 in FIG. 2.

FIG. 5 is a fragmentary sectional view taken along the line 5-5 in FIG. 2.

FIG. 6 is a fragmentary sectional view taken along the line 6--6 inFlG. 2.

FIG. 7 is a fragmentary sectional view taken along the line 7-7 in FIG. 2.

FIG. 8'is a fragmentary sectional view taken along the line 8-8 in FIG. 2.' I

DESCRIPTION Referring to FIG. 3, the towftruck conveyor system embodying the invention comprises a floor 10 having a slot 11 along which tow trucks 12 are adapted to be driven by engagement of tow pins 13 on the towtrucks 12 with a conveyor 14 driven along a track 15 beneath the floor 10 and the slot 11 (FIGS. land 2).

At one point along the slot 11, a mechanical stop apparatus 16 is provided. The mechanical stop apparatus comprises a housing 17 including a bottom wall 18, side walls 19 and end walls 20 (FIG. 4). The apparatus 16 includes a transversely movable track section 21 (FIGS.'1 and 2) that is adapted to move the chain conveyor 14 transversely and cause the tow pin 13 to be cammed upwardly by a cam portion 22, as

presentlydescribed. 7

Referring to FIGS. 1, 2 and 4, the conveyor 14 comprises links =23 that are pivoted to one another. At least some of the upper links 23a have a recess 24 (FIGS. 1 and 4) for engaging the tow pin 13 to drive the tow pin and, in turn, the tow truck. along the floor. 1

Track section 21 comprises a base plate 25 and spaced vertical walls 26, 27 that define a U-shaped track (FIG. 2). The leading end of the wall 27 is tapered upwardly and forwardly to form the cam 22. When the track section 21 is in the position shown in FIG. 2, as the chain conveyor 14 moves along, the tow pin 13 engages the inclined cam 22 and is forced upwardly onto the cam 22 to the position A as shown in broken lines in FIG. 2.

In this position, pin 13 partially overlaps the cam 22 and wall 27 of track 21. At this point, the tow pin 13 is out of driving engagement with the chain conveyor 14. When it is desired to re-engage the tow pin 13 with the chain conveyor 14, the track section 21 is moved from the position shown in FIG. 2 to the position shown in FIG. 2 permitting the tow pin 13 to drop downwardly for engagement with .a succeeding slot 24 of a link of the chain conveyor 14.

As shown in FIGS. 1, 2 and 4, means are provided for guiding the transverse movement of the track section 21 and comprise guide members 30 mounted on the plate 25 and having their edges 31 engaging rollers 32 that are mounted for rotation about vertical axes on a bar 33 fastened to the bottom wall 18 of the housing 16. In addition, downwardly turned flanges 34 on plate 25 engage the vertical walls of angles 35 fixed on bottom wall 18 to also guide the track section.

The means for moving the track section 21 laterally of the longitudinal direction of movement of the chain conveyor 14 comprises a mechanismthat includes an L-shaped lever arm 37 which has legs 38, 39. Leg 38 of lever arm 37 is pivoted at its end to the plate 25 by a bolt 40. Leg 38 is yieldingly urged counterclockwise as viewed in FIG. 1 by a spring 59 interposed between a bracket 60 and an adjustable nut 61 on a shaft 62, one end of which is pivoted to the leg 38 as at 63 and the other end of which extends through an opening 64 in bracket 60. A cam plate 41 having a tapered surface 42 facing'the oncoming tow pin 13 is provided on the free end of the leg 39 of lever arm 37. The free end of lever arm 38 is pivoted by a pin 42 to a link 43. The pin 42 supports a roller 44 (FIG. 6). The other end of the link 43 is pivoted at 45 to the base 18 of the housing. A latch 46 is pivoted to a bracket 47 and yieldingly urged by a spring 48 on a guide pin 49 in a manner such that a surface 50 on the end thereof engages the roller 44. The pin 49 extends through an opening 51 in a bracket 52 and the spring 48 is interposed between thebracket 52 and a flange 53a on the pin (FIG. 8). Latch 46 includes a notch 54. As shown in FIGS. 1, 2 and 7, a solenoid S is mounted on plate 25 and its plunger Pis adapted to engage latch 46 to hold notch 54'so that it will not engage roller 44. An anti-backup lever 56 is pivoted at 57 and yieldingly urged in a counterclockwise direction as shown in FIG. 1 by a spring 58 and functions to prevent retrograde movement of the tow pin 13 when the tow pin is on the wall 27.

In operation, as the chain conveyor 14 brings a tow pin 13 into the stop apparatus 16. the tow pin 13 strikes the cam plate 41 swinging lever 37 to move link 43 into position for engagement by latch 46. Simultaneously, with the above action, the slidable track section 21 and the portion of conveyor chain 14 within it is moved transversely to the direction of conveyor travel forcing the tow pin 13 to engage the inclined portion of cam 22. The tow pin 13 will thus be disengaged from conveyor 14 and come to a stopsomewhere between position A and adjacent to stop block 55 on top of vertical wall 27. When it is desired to reengage the tow pin with the chain, solenoid S is energized to move latch 46 and release the link 43 to cause the spring 59 to return the track section 21 to the position shown in F IG. 1 and permit the tow pin 13 to drop on top of conveyor chain 14 for pick up by the next link 23a. When it is intended that the tow truck 12' not be interrupted, the solenoid S is energized so that although the lever 37 is actuated by the tow pin, the link 43 will not be engaged by the latch 46.

We claim:

1. In a tow truck conveyor system wherein a plurality of tow trucks are provided, each having a tow pin extending downwardly through a slot in the floor, the combination compnsrng a chain track adapted to be positioned beneath said slot,

a conveyor chain extending and driven along said chain track,

said chain having tow pin engaging means thereon,

a section of said chain track being movable transversely with respect to the longitudinal movement of the chain along said track,

tow pin directing means associated with said movable track portion and movable therewith to and from positions into and out of the path of the tow pin as it approaches the movable portion,

and means for moving said movable section to and from said positions,

said tow pin directing means comprising cam means mounted on said track section in the path of the tow pin,

said cam means being movable with said track section to bring it into and out of the path of said tow pin,

said cam means when in the path of said tow pin being engaged by said tow pin to move said tow pin upwardly,

and latch means for locking said movable track section and,

in turn, said chain out of its normal path,

means for interconnecting said cam means and said latch means,

and means for disabling said latch means when it is desired to have said tow pin move in its normal path.

2. For use in a tow truck conveyor system including a plurality of tow trucks each having a tow pin extending downwardly through a slot in the floor, a chain track adapted to be positioned beneath said slot, and a conveyor chain extending and driven along said chain track, said chain having tow pin engaging means thereon,

a stop mechanism comprising a housing,

a track section,

cam means mounted on said track section in the path of the tow pin,

said cam means being movable with said track section to bring it into and out of the path ofsaid tow pin,

said cam means when in the path of said tow pin being engaged by said tow pin to move said tow pin upwardly,

and latch means for locking said last-mentioned means in position to hold said movable track section and, in turn, a chain out of its normal position,

means interconnecting said cam means and said latch means,

and means for disabling said latch means when it is desired to have said tow pin move in its normal path.

3. In a tow truck conveyor system wherein a plurality of tow trucks are provided, each having a tow pin extending downwardly through a slot in the floor, the combination comprising a chain track adapted to be positioned beneath said slot,

a conveyor chain extending and driven along said chain track,

said chain having tow pin engaging means thereon,

a section of said chain track being movable transversely with respect to the longitudinal movement of the chain along said track,

tow pin directing means associated with said movable track portion and movable therewith to and from positions into and out of the path of the tow pin as it approaches the movable portion,

and means for moving said movable section to and from said positions,

cam means mounted on said track section in the path of the tow pin,

and latch means for locking said movable track section and,

in turn, said chain out of its normal path,

means for interconnecting said cam means and said latch means,

and means for disabling said latch means when it is desired to have said tow pin move in its normal path,

said interconnecting means comprising a toggle mechanism comprising a pair of levers pivoted to one another at one end,

the other end of one of said levers being pivoted to said track portion, the other end of the other said lever being pivoted to a fixed portion,

and said cam means being connected to said one lever.

4. The combination set forth in claim 3 wherein said one first mentioned lever is L-shaped.

5. The combination set forth in claim 4 wherein said cam means is mounted on said L-shaped lever.

6. The combination set forth in claim 5 wherein said cam means comprises a cam plate projecting into the path of the tow pin.

7. The combination set forth in claim 3 wherein said latch means comprises a latch member engageable with said other lever.

8. The combination set forth in claim 7 wherein said latch member has a notch therein, said other lever having a member engageable by said notch in one position of said other lever.

9. The combination set forth in claim 8, said means for disabling said latch means being operable on said latch member.

10. The combination set forth in claim 9 wherein said disabling means comprises a solenoid.

1 1. For use in a tow truck conveyor system including a plurality of tow trucks each having a tow pin extending downwardly through a slot in the floor, a chain track adapted to be positioned beneath said slot, and a conveyor chain extending and driven along said chain track, said chain having tow pin engaging means thereon,

a stop mechanism comprising a housing,

a track section,

cam means mounted on said track section in the path of the tow pin,

and latch means for locking said last-mentioned means in position to hold said movable track section and, in turn, a chain out of its normal position,

means interconnecting said cam means and said latch means,

and means for disabling said latch means when it is desired to have said tow pin move in its normal path,

said interconnecting means comprising a toggle mechanism comprising a pair of levers pivoted to one another at one end,

the other end of one of said levers being pivoted to said track portion,

the other end of the other said lever being pivoted to a fixed portion,

and said cam means being connected to said one lever.

12. The combination set forth in claim 11 wherein said one lever is L-shaped.

13. The combination set forth in claim 12 wherein said cam means is mounted on said L-shaped lever.

14. The combination set forth in claim 13 wherein said cam means comprises a cam plate projecting into the path of the tow pin.

15. The combination set forth in claim 11 wherein said latch means comprises a latch member engageable with said other lever.

16. The combination set forth in claim 15 wherein said latch member has a notch therein, said other lever having a member engageable by said notch in one position of said other lever.

17. The combination set forth in claim 16, said means for disabling said latch means being operable on said latch member.

18. The combination set forth in claim 17 wherein said disabling means comprises a solenoid. 

1. In a tow truck conveyor system wherein a plurality of tow trucks are provided, each having a tow pin extending downwardly through a slot in the floor, the combination comprising a chain track adapted to be positioned beneath said slot, a conveyor chain extending and driven along said chain track, said chain having tow pin engaging means thereon, a section of said chain track being movable transversely with respect to the longitudinal movement of the chain along said track, tow pin directing means associated with said movable track portion and movable therewith to and from positions into and out of the path of the tow pin as it approaches the movable portion, and means for moving said movable section to and from said positions, said tow pin directing means comprising cam means mounted on said track section in the path of the tow pin, said cam means being movable with said track section to bring it into and out of the path of said tow pin, said cam means when in the path of said tow pin being engaged by said tow pin to move said tow pin upwardly, and latch means for locking said movable track section and, in turn, said chain out of its normal path, means for interconnecting said cam means and said latch means, and means for disabling said latch means when it is desired to have said tow pin move in its normal path.
 2. For use in a tow truck conveyor system including a plurality of tow trucks each having a tow pin extending downwardly through a slot in the floor, a chain track adapted to be positioned beneath said slot, and a conveyor chain extending and driven along said chain track, said chain having tow pin engaging means thereon, a stop mechanism comprising a housing, a track section, cam means mounted on said track section in the path of the tow pin, said cam means being movable with said track section to bring it into and out of the path of said tow pin, said cam means when in the path of said tow pin being engaged by said tow pin to move said tow pin upwardly, and latch means for locking said last-mentioned means in position to hold said movable track section and, in turn, a chain out of its normal position, means interconnecting said cam means and said latch means, and means for disabling said latch means when it is desired to have said tow pin move in its normal path.
 3. In a tow truck conveyor system wherein a plurality of tow trucks are provided, each having a tow pin extending downwardly through a slot in the floor, the combination comprising a chain track adapted to be positioned beneath said slot, a conveyor chain extending and driven along said chain track, said chain having tow pin engaging means thereon, a section of said chain track being movable transversely with respect to the longitudinal movement of the chain along said track, tow pin directing means associated with said movable track portion and movable therewith to and from positions into and out of the path of the tow pin as it approaches the movable portion, and means for moving said movable section to and from said positions, cam means mounted on said track section in the path of the tow pin, and latch means for locking said movable track section and, in turn, said chain out of its normal path, means for interconnecting said cam means and said latch means, and means for disabling said latch means when it is desired to have said tow pin move in its normal path, said interconnecting means comprising a toggle mechanism comprising a Pair of levers pivoted to one another at one end, the other end of one of said levers being pivoted to said track portion, the other end of the other said lever being pivoted to a fixed portion, and said cam means being connected to said one lever.
 4. The combination set forth in claim 3 wherein said one first mentioned lever is L-shaped.
 5. The combination set forth in claim 4 wherein said cam means is mounted on said L-shaped lever.
 6. The combination set forth in claim 5 wherein said cam means comprises a cam plate projecting into the path of the tow pin.
 7. The combination set forth in claim 3 wherein said latch means comprises a latch member engageable with said other lever.
 8. The combination set forth in claim 7 wherein said latch member has a notch therein, said other lever having a member engageable by said notch in one position of said other lever.
 9. The combination set forth in claim 8, said means for disabling said latch means being operable on said latch member.
 10. The combination set forth in claim 9 wherein said disabling means comprises a solenoid.
 11. For use in a tow truck conveyor system including a plurality of tow trucks each having a tow pin extending downwardly through a slot in the floor, a chain track adapted to be positioned beneath said slot, and a conveyor chain extending and driven along said chain track, said chain having tow pin engaging means thereon, a stop mechanism comprising a housing, a track section, cam means mounted on said track section in the path of the tow pin, and latch means for locking said last-mentioned means in position to hold said movable track section and, in turn, a chain out of its normal position, means interconnecting said cam means and said latch means, and means for disabling said latch means when it is desired to have said tow pin move in its normal path, said interconnecting means comprising a toggle mechanism comprising a pair of levers pivoted to one another at one end, the other end of one of said levers being pivoted to said track portion, the other end of the other said lever being pivoted to a fixed portion, and said cam means being connected to said one lever.
 12. The combination set forth in claim 11 wherein said one lever is L-shaped.
 13. The combination set forth in claim 12 wherein said cam means is mounted on said L-shaped lever.
 14. The combination set forth in claim 13 wherein said cam means comprises a cam plate projecting into the path of the tow pin.
 15. The combination set forth in claim 11 wherein said latch means comprises a latch member engageable with said other lever.
 16. The combination set forth in claim 15 wherein said latch member has a notch therein, said other lever having a member engageable by said notch in one position of said other lever.
 17. The combination set forth in claim 16, said means for disabling said latch means being operable on said latch member.
 18. The combination set forth in claim 17 wherein said disabling means comprises a solenoid. 